It is well-known that self-propelled swathers include a tractor in the form of a tractor frame carried on a pair of widely spaced front driven ground wheels together with widely spaced rear castor wheels. At the front of the frame is mounted a header extending across the frame for cutting the standing crop with the header generally having components which convey the crop material inwardly to a discharge opening between the front wheels so that the crop material is discharged in a windrow or swath between the wheels of the tractor.
In some cases the tractor carries a set of conditioning rollers behind the discharge opening for the crop material to be crushed or otherwise conditioned from improved drying action.
It is becoming more popular to utilize a conveyor underneath the frame of the tractor which acts, when activated, to transport the windrow from a position underneath the frame to a position of one side of the frame so that the windrow can be combined with another window or more than one windrow where other windrows are arranged alongside one another to be picked up simultaneously either for collection in a forage harvesting system or for baling.
A number of different arrangements are known for this conveyor which is also commonly known as a “double windrow attachment” or “DWA”.
In U.S. Pat. No. 5,031,393 (Rostoucher) issued Jul. 16, 1996; U.S. Pat. No. 5,351,468 (Pominville) issued Oct. 4, 1994; U.S. Pat. No. 6,145,289 (Welsch) issued Nov. 14, 2000 and U.S. Pat. No. 6,679,038 (Walch) issued Jan. 20, 2004 are provided designs of double windrow attachment for windrowers which allow movements generally upwardly and downwardly from a lowered operating position to a raised retracted position.
In U.S. Pat. No. 6,415,590 (Lohrentz) issued Jul. 9, 2002 is shown a self-propelled windrower where the conveyor has a fixed rear beam along a rear edge of the upper run of the belt and pivots about this fixed beam so that the front edge of the belt pivots upwardly and forwardly from a lowered operating position in which the belt is inclined forwardly and downwardly to a raised retracted position.
Another arrangement mounted on a self-propelled tractor is shown in drawings of a device manufactured by Assignee of the present application in which the conveyor does not pivot about a fixed axis but instead is mounted on links which allow the whole conveyor to move upwardly and forwardly from the lowered operating position to a raised position. This design is based upon a previous arrangement manufactured by Sharp's Welding and Mechanical Works in Stanfield, Ariz. The Sharp's device is also shown in photographs.
It is highly desirable that the conveyor be movable from an operating position in which the conveyor belt is inclined forwardly and downwardly and extends across the frame to a retracted position in which the conveyor is removed from the path of the crop material. However this movement is seriously constrained by the construction of tractor in that the conveyor in both positions must be clear of the wheels and must move to a properly retracted position and to a properly located operating position.